The Hollowed Out Concretion Cave

 

I’ve always been obsessed with concretions, and honestly, New Zealand is probably the best place on earth to hunt for them. On a recent trip, I was scouting a particularly rugged stretch of coast right at low tide. Way off in the distance, I spotted a shape that looked like a massive concretion…easily one of the largest I’ve ever come across.As I got closer, it got even better. To my total surprise, one end had been naturally cracked open by the elements. Over time, the seawater had worked its way inside and completely hollowed the thing out. It’s actually large enough to climb into. It’s basically a miniature cave with its own self-contained ecosystem living inside the shell. It felt like stepping into a tiny, secret world.